Surveying proteolytic processes in human cancer microenvironments by microdialysis and activity-based mass spectrometry.

ABSTRACT: We present a strategy to survey proteolytic processes that occur in human cancer microenvironments.In situ microdialysis during oral cancer surgery was combined with mass spectrometry-based proteomics to analyze interstitial fluid surrounding tumors and anatomically matched normal sites. Protease activity-based (18)O-profiling was utilized to reveal peptides that were processed by co-collected proteases ex vivo.We demonstrated for the first time the use of microdialysis in humans to collect interstitial fluid from cancer microenvironments. Proteomic profiling identified proteases and inhibitors in the microdialysis samples. A subset of peptides displayed characteristic (18)O-isotope patterns that indicated processing by endogenous proteases.The presented approach provides unprecedented views of in vivo targets of proteases without disrupting the cancer or surrounding tissue. The methodology can be broadly adapted to other physiological conditions in which proteolytic mediators are involved (e.g. arthritic joints, inflamed muscle, other types of cancer) and where a comparison of normal and pathological tissue is sought.

SUBMITTER: Hardt M 

PROVIDER: S-EPMC3470480 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature